How can structure and composition of Eucalyptus plantation landscape reduce leaf-cutting ants?

Abstract

Leaf-cutting ants (Atta spp.) are the main Eucalyptus plantation pests that cause successive defoliation, and productivity losses might be significant. Thus, our objective was to evaluate the influence of vegetation composition and landscape structure on the occurrence of leaf-cutting ants in Eucalyptus spp. plantations neighboring areas of Atlantic Forest vegetation. We collected data on the occurrence of ants (Atta spp.) and the amount of loose soil in each ant colony. We calculated the landscape metrics for the area that we divided in landscape planning unit. We proceeded with information-theoretic approach to identify the best set of models with AICc criteria. We found that 81.1% of the ant colonies had an area of loose soil smaller than 1 m2, and the diversity of Eucalyptus ages, edges of Eucalyptus plantation, and conservation of native fragments have influence on ant occurrence and reduce their effects. So, an increase in vegetation conservation status, decrease of roads that lead to edges in Eucalyptus plantations, and adoption of age mosaics in production areas disrupts ant occurrence. In addition, better functional and structural conditions favor ecosystem services, such as soil and water conservation, through a reduction in the use of formicidal baits.